Conference_programme: 23: Structural acoustics and vibration
Lecture: Biodynamics of the human body under hand-arm vibration: development of a biomechanical model
Author(s): Picu Laurentiu
Summary:
This paper analyses the vibrations produced by various portable technological equipment on the hand-arm system of workers who use this type of tools. We used the values obtained from the measurements or average values which were taken from the specialized literature. Determination of actual values for the key parameters corresponding to the adopted geometric configuration was made on 3D models. Analysing the general structure of the proposed virtual model, five main modules are determined, namely: three modules for hand, arm, and forearm simulation, a module simulating excitation signals and a module containing graphical (and tabular) evolution of the analyzed signals. It is considered that the direct way of propagating the disturbing dynamic action from the source to the human receptor is the hand - forearm - arm system. A series of signals, that can be used to simulate and analyze the behavior of this virtual model, were studied: classical signals (impulse, step, and harmonic function), periodic signals, etc. The degree of utility of each type of signal results from the type of the developed analysis and from the initial imposed requirements. Thus can be determined: the weighted response, the transfer function, the indicative response, the harmonic and/or the poly-harmonic response, the statistical response, the spectral characteristic, etc. An important conclusion is that, in the case of dynamic external disturbances, the maximum strains are found in the arm. The forearm (hand included) is stressed in accordance with the applied restriction and (as seen in the diagrams set) it fully respects the imposed motion law, even if the strains in this element are exclusively externally imposed. For the body, the relative large mass to the other two elements, along with the relatively low external stresses, makes the movement acquired during the analysis very low, negligible in most cases. This also indicates a significant conclusion for this study, namely that the hand-arm transmission path has the ability to be tuned both with the excitation and with the "receiver" thereby ensuring a very low transmissibility of the external disturbance to the body and the dynamic effects felt by to be minimized.
Corresponding author
Name: Mr Laurentiu Picu
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Romania
